52 research outputs found
Payload IVA training and simulation
The development of a training program for the intravehicular operation of space shuttle payloads is discussed. The priorities for the program are compliance with established training standards, and accommodating changes. Simulation devices are also reviewed
Policies and practices of SHEA Research Network hospitals during the COVID-19 pandemic
To understand hospital policies and practices as the COVID-19 pandemic accelerated, the Society for Healthcare Epidemiology of America (SHEA) conducted a survey through the SHEA Research Network (SRN). The survey assessed policies and practices around the optimization of personal protection equipment (PPE), testing, healthcare personnel policies, visitors of COVID-19 patients in relation to procedures, and types of patients. Overall, 69 individual healthcare facilities responded in the United States and internationally, for a 73% response rate
Productive osseous changes about the wrist in rheumatoid arthritis
Radiographs of 225 consecutive patients with adult-form rheumatoid arthritis were examined for evidence of productive osseous changes about the wrist. The prevalence of new bone on the ulnar styloid was 10%. This form of new bone is probably due to overlying chronic tenosynovitis. A collar of new bone around the ulnar head is a result of degenerative change in the distal radioulnar joint. In general, productive osseous changes in rheumatoid arthritis may represent inflammatory periosteal bone formation, osteophytosis, or contact remodeling. We found no evidence of an association between diffuse idiopathic skeletal hyperostosis and extensive productive osseous changes in patients with rheumatoid arthritis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46784/1/256_2004_Article_BF00350967.pd
Informed Conditioning on Clinical Covariates Increases Power in Case-Control Association Studies
Genetic case-control association studies often include data on clinical covariates, such as body mass index (BMI), smoking status, or age, that may modify the underlying genetic risk of case or control samples. For example, in type 2 diabetes, odds ratios for established variants estimated from low–BMI cases are larger than those estimated from high–BMI cases. An unanswered question is how to use this information to maximize statistical power in case-control studies that ascertain individuals on the basis of phenotype (case-control ascertainment) or phenotype and clinical covariates (case-control-covariate ascertainment). While current approaches improve power in studies with random ascertainment, they often lose power under case-control ascertainment and fail to capture available power increases under case-control-covariate ascertainment. We show that an informed conditioning approach, based on the liability threshold model with parameters informed by external epidemiological information, fully accounts for disease prevalence and non-random ascertainment of phenotype as well as covariates and provides a substantial increase in power while maintaining a properly controlled false-positive rate. Our method outperforms standard case-control association tests with or without covariates, tests of gene x covariate interaction, and previously proposed tests for dealing with covariates in ascertained data, with especially large improvements in the case of case-control-covariate ascertainment. We investigate empirical case-control studies of type 2 diabetes, prostate cancer, lung cancer, breast cancer, rheumatoid arthritis, age-related macular degeneration, and end-stage kidney disease over a total of 89,726 samples. In these datasets, informed conditioning outperforms logistic regression for 115 of the 157 known associated variants investigated (P-value = 1×10−9). The improvement varied across diseases with a 16% median increase in χ2 test statistics and a commensurate increase in power. This suggests that applying our method to existing and future association studies of these diseases may identify novel disease loci
Aquaponics in the Built Environment
Aquaponics’ potential to transform urban food production has been documented in a rapid increase of academic research and public interest in the field. To translate this publicity into real-world impact, the creation of commercial farms and their relationship to the urban environment have to be further examined. This research has to bridge the gap between existing literature on growing system performance and urban metabolic flows by considering the built form of aquaponic farms. To assess the potential for urban integration of aquaponics, existing case studies are classified by the typology of their building enclosure, with the two main categories being greenhouses and indoor environments. This classification allows for some assumptions about the farms’ performance in their context, but a more in-depth life cycle assessment (LCA) is necessary to evaluate different configurations. The LCA approach is presented as a way to inventory design criteria and respective strategies which can influence the environmental impact of aquaponic systems in the context of urban built environments
Chapitre 14: Phytopathogènes et stratégies de contrôle en aquaponie
peer reviewedAmong the diversity of plant diseases occurring in aquaponics, soil-borne
pathogens, such as Fusarium spp., Phytophthora spp. and Pythium spp., are the most
problematic due to their preference for humid/aquatic environment conditions.
Phytophthora spp. and Pythium spp. which belong to the Oomycetes pseudo-fungi
require special attention because of their mobile form of dispersion, the so-called
zoospores that can move freely and actively in liquid water. In coupled aquaponics,
curative methods are still limited because of the possible toxicity of pesticides and
chemical agents for fish and beneficial bacteria (e.g. nitrifying bacteria of the
biofilter). Furthermore, the development of biocontrol agents for aquaponic use is
still at its beginning. Consequently, ways to control the initial infection and the
progression of a disease are mainly based on preventive actions and water physical
treatments. However, suppressive action (suppression) could happen in aquaponic
environment considering recent papers and the suppressive activity already
highlighted in hydroponics. In addition, aquaponic water contains organic matter
that could promote establishment and growth of heterotrophic bacteria in the system
or even improve plant growth and viability directly. With regards to organic
hydroponics (i.e. use of organic fertilisation and organic plant media), these bacteria
could act as antagonist agents or as plant defence elicitors to protect plants from
diseases. In the future, research on the disease suppressive ability of the aquaponic
biotope must be increased, as well as isolation, characterisation and formulation of
microbial plant pathogen antagonists. Finally, a good knowledge in the rapid
identification of pathogens, combined with control methods and diseases monitoring,
as recommended in integrated plant pest management, is the key to an efficient
control of plant diseases in aquaponics.Cos
Efficient Adaptively Weighted Analysis of Secondary Phenotypes in Case-Control Genome-Wide Association Studies
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